JP5899073B2 - Styrene-isoprene copolymer and method for producing the same - Google Patents

Description

  The present invention relates to a styrene-isoprene copolymer and a method for producing the same.

In recent years, in order to save automobile fuel consumption in response to social demands for energy and resource saving, many rubber materials with excellent fracture resistance, wear resistance, and crack growth resistance have been developed due to tire durability requirements. It has come to be desired. In addition, the price of natural rubber has risen, and the development of synthetic rubber having durability equivalent to that of natural rubber is required. Synthetic polyisoprene has been conventionally used as an alternative to natural rubber. However, when synthetic polyisoprene is used as a rubber composition, there is a problem that it is inferior in durability to natural rubber. Therefore, in order to improve durability, conventionally, improvement of elongation crystallinity has been performed by increasing the cis of synthetic polyisoprene (see, for example, Patent Documents 1 and 2).
Further, a technique for improving desired rubber characteristics by kneading synthetic polyisoprene with other polymer components or using a copolymer of isoprene and other monomers is known. Patent Document 3 discloses a tire tread rubber composition comprising a styrene-isoprene copolymer and a styrene-butadiene copolymer.

JP 2004-27179 A International Publication No. 2006-078021 Pamphlet JP-A-5-255540

  An object of the present invention is to provide a styrene-isoprene copolymer capable of obtaining a rubber composition having natural rubber-like characteristics (for example, durability (breakage resistance, abrasion resistance, and crack growth resistance)), and It is in providing the manufacturing method. Another object of the present invention is to provide a rubber composition having the above styrene-isoprene copolymer and a tire using the rubber composition.

In order to solve the above-mentioned problems, in the present invention, a styrene-isoprene copolymer having a styrene block at the terminal, the ratio of the styrene monomer to the total monomer constituting the copolymer is 1.7 to 3 The copolymer is characterized in that the amount of cis-1,4 bonds in the portion derived from isoprene is 95% or more in total. Since the amount of styrene contained in the copolymer is below a certain level, the natural rubber-like properties of polyisoprene are maintained. Further, by increasing the amount of cis-1,4 bonds in the portion derived from isoprene, it is possible to obtain a rubber having more natural rubber-like characteristics and excellent durability.

  In the styrene-isoprene copolymer, the number of styrene monomer units per styrene block is preferably 10 or less. Moreover, it is preferable that the molecular weight per styrene block is 1000 or less. If the styrene block in the copolymer is too large, the characteristics of polyisoprene are likely to be impaired. By keeping the size of the styrene block below a certain level, it is possible to maintain its durability (breakage resistance, wear resistance, crack growth resistance).

  The styrene-isoprene copolymer can be suitably formed by polymerizing a styrene monomer in the presence of a catalyst to synthesize a polymer or oligomer, and adding the isoprene monomer to the polymer or oligomer for polymerization. is there. In this way, in the polymerization of styrene and isoprene in the same system, the synthesis process of the copolymer is divided into two stages. In the styrene polymerization process, it is formed by increasing or decreasing the reaction temperature and reaction time. The size of the styrene block can be adjusted as appropriate, and the microstructure can be easily controlled in the isoprene polymerization step. Although such a fine adjustment is possible by the manufacturing method, it can be carried out easily in one pot.

The production method of the styrene-isoprene copolymer of the present invention is represented by the following formula (i):
M- (NQ) ¹ (NQ) ² (NQ) ³ (i)
(In the formula, M is at least one selected from lanthanoids, scandium and yttrium, and NQ ¹ , NQ ² and NQ ³ are amide groups, which may be the same or different, provided that MN A polymer or oligomer is synthesized by polymerizing a styrene monomer at −100 ° C. to 200 ° C. in the presence of a catalyst containing a rare earth element compound represented by (having a bond), and isoprene monomer is added to the polymer or oligomer Then, a method for producing a styrene-isoprene copolymer that is polymerized at −100 ° C. to 200 ° C. , wherein the ratio of the styrene monomer to the total monomers constituting the styrene-isoprene copolymer is 1.7 to 3. The amount of cis-1,4 bonds in the portion derived from isoprene is 95% or more as a whole.

The catalyst contains a rare earth element compound represented by the above formula (i) .
By using a catalyst containing the rare earth element compound, a styrene-isoprene copolymer can be efficiently produced without requiring an isolation step of the catalyst composition. By using a rare earth element compound containing a nitrogen atom as a catalyst, the catalyst itself has high stability. Due to its high stability, the catalyst composition can be effectively produced in-situ without going through a special reactor or synthesis process. It is possible to form an object. Thereby, since the isolation step of the catalyst composition can be omitted, the yield of the catalyst is increased, and the styrene-isoprene copolymer can be efficiently produced.
In the present specification, the “rare earth element” refers to a lanthanoid element, scandium, or yttrium.

  In the method for producing a copolymer of the present invention, it is preferable to add an additive D that can be an anionic ligand. By adding the additive D, a polymer composition having a high cis-1,4 bond amount can be obtained in a high yield.

  The rubber composition of the present invention comprises any one of the above polymer compositions in an amount of 50 parts by weight or more based on 100 parts by weight of the rubber component. By blending 50 parts by weight or more of the above polymer composition, it is possible to provide a rubber composition having improved durability (destructive properties, wear resistance, and crack growth resistance).

  The tire of the present invention includes a rubber member using the rubber composition. When the tire is provided with a rubber member using the rubber composition, the durability (destruction resistance, wear resistance, and crack growth resistance) of the tire can be improved.

  According to the present invention, it is possible to produce a rubber having natural rubber-like properties (durability (destructive properties, wear resistance, and crack growth resistance)). Further, it is possible to provide a rubber composition and a tire having excellent durability (breakage resistance, wear resistance, and crack growth resistance).

(Styrene-isoprene copolymer)
The copolymer of the present invention is a styrene-isoprene copolymer. Hereinafter, it is also simply referred to as “copolymer”.
The copolymer has a styrene block at a terminal. The term “terminal” as used herein refers to either one end or both ends of the copolymer main chain. That is, it has a styrene block at least at one end of the copolymer main chain.
In the styrene-isoprene copolymer, if the proportion of the styrene portion (hard segment) is too large, the natural rubber-like advantages of polyisoprene such as durability cannot be sufficiently achieved. Polyisoprene is required to exhibit a high cis content in its microstructure in order to have natural rubber-like properties. In conventional styrene-isoprene copolymers, the styrene content in the copolymer is reduced. A technique for making the isoprene portion highly cis while adjusting was not studied at all.
Styrene in the copolymer is detected using NMR and GPC. When NMR is used, since the phenyl proton of styrene is observed in the vicinity of 7 ppm, the ratio with the detected value of isoprene is calculated to confirm the abundance of styrene. In the case of GPC, the ratio between the isoprene detection value and the styrene detection value (absorption at 254 nm) is calculated using the absorption peak at 254 nm of styrene.

-Chain structure-
The chain structure other than the terminal portion of the copolymer is not particularly limited and can be appropriately selected according to the purpose. For example, a block copolymer, a random copolymer, a tapered copolymer, an alternating copolymer, etc. Is mentioned. However, as described later, since the copolymer of the present invention contains a small amount of styrene monomer units, it is preferable to use a polyisoprene structure other than the terminal portion and a so-called block copolymer-like structure.

--Block copolymer--
The block copolymer has a structure of (AB) _x , A- (BA) _x and B- (AB) _x (where A is a block part composed of monomer units of isoprene). And B is a block portion made of styrene, and x is an integer of 1 or more. In addition, the block copolymer provided with two or more structures of (AB) or (BA) is called a multi-block copolymer.

--Random copolymer--
The structure of the random copolymer is a structure in which isoprene monomer units and styrene monomer units are randomly arranged.

--Tapered copolymer--
The taper copolymer is a copolymer in which a random copolymer and a block copolymer are mixed, and at least one of a block portion composed of a monomer unit of isoprene and a block portion composed of styrene. It is a copolymer composed of a block portion (also referred to as a block structure) and a random portion (referred to as a random structure) in which monomer units of isoprene and styrene are randomly arranged.
The structure of the tapered copolymer indicates that the composition of the isoprene component and the styrene component is distributed continuously or discontinuously.

--Alternate copolymer--
The alternating copolymer has a structure in which isoprene and styrene are alternately arranged (molecular chain structure of -ABABABAB- when A is the monomer unit of isoprene and B is the monomer unit of styrene). It is a polymer having.

-Styrene content-
In the copolymer of the present invention, the proportion of styrene in all monomer units constituting the copolymer is 1.7 to 3.3 mol% . By making styrene less than 5 mol%, there is an advantage that durability (breakage resistance, wear resistance, and crack growth resistance) can be improved without losing the characteristics of isoprene.

-Cis-1,4 binding amount-
The isoprene-derived portion in the copolymer has a total cis-1,4 bond content of 95% or more, preferably 97% or more, more preferably 98% or more. If it is 95% or more, sufficient stretch crystallinity can be expressed.
On the other hand, when the amount of cis-1,4 bonds is within the more preferable range or the particularly preferable range, it is advantageous in terms of improvement in durability due to stretched crystallinity.
The amount of cis-1,4 bonds (the amount of trans-1,4 bonds and 3,4-vinyl bonds described later) is the amount in the isoprene-derived portion, and is based on the entire isoprene copolymer. It is not a percentage.

-Trans-1,4 binding amount-
There is no restriction | limiting in particular as trans-1,4 bond amount of the isoprene origin part in the said copolymer, Although it can select suitably according to the objective, 5% or less is preferable and 3% or less is more preferable.
When the amount of the trans-1,4 bond is 1% or less, more sufficient stretched crystallinity can be expressed.
On the other hand, when the amount of the trans-1,4 bond is in the more preferable range or the particularly preferable range, it is further advantageous in terms of improvement in durability due to stretched crystallinity.

−3,4-vinyl bond amount−
The amount of 3,4-vinyl bond in the isoprene-derived portion in the copolymer is not particularly limited and can be appropriately selected according to the purpose, but is preferably 5% or less, more preferably 3% or less, 1% or less is particularly preferable.
When the 3,4-vinyl bond amount is 5% or less, more sufficient stretch crystallinity can be expressed.
On the other hand, when the 3,4-vinyl bond amount is within the more preferable range or the particularly preferable range, it is further advantageous in terms of improvement in durability due to stretched crystallinity.

-1,2-vinyl bond amount-
The amount of 1,2-vinyl bond in the isoprene-derived portion in the copolymer is not particularly limited and can be appropriately selected according to the purpose, but is preferably 5% or less, more preferably 3% or less, 1% or less is particularly preferable.
When the amount of 1,2-vinyl bonds is 5% or less, sufficient stretch crystallinity can be expressed.
On the other hand, when the amount of 1,2-vinyl bonds is within the more preferable range, it is advantageous in terms of improving durability due to stretched crystallinity.

-Number average molecular weight-
The number average molecular weight (Mn) of the copolymer is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 400,000 to 2.5 million, and more preferably 500,000 to 2.5 million. By setting the molecular weight to 2.5 million or less, good processability can be maintained. The number average molecular weight (Mn) is determined using polystyrene as a standard substance by gel permeation chromatography (GPC).

-Molecular weight distribution (Mw / Mn)-
The molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the copolymer is not particularly limited and can be appropriately selected according to the purpose. 1 to 5 are preferable. Here, the molecular weight distribution (Mw / Mn) is determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.

-Method for producing styrene-isoprene copolymer-
Next, a production method capable of producing the styrene-isoprene copolymer will be described in detail. The method for producing a copolymer of the present invention includes at least a polymerization step, and further includes a coupling step, a washing step, and other steps that are appropriately selected as necessary. In the production of the copolymer, it is preferable to polymerize the styrene monomer in the presence of the catalyst without adding isoprene and adding only the styrene monomer in the first polymerization step. In particular, when a polymerization catalyst composition described later is used, it is difficult to polymerize styrene in the presence of a styrene monomer and an isoprene monomer because isoprene is more reactive than styrene. In addition, it is likely that it is difficult to polymerize isoprene first and then additionally polymerize styrene later due to the characteristics of the catalyst.

--- Polymerization method--
As a polymerization method, any method such as a solution polymerization method, a suspension polymerization method, a liquid phase bulk polymerization method, an emulsion polymerization method, a gas phase polymerization method, and a solid phase polymerization method can be used. Moreover, when using a solvent for a polymerization reaction, the solvent used should just be inert in a polymerization reaction, For example, toluene, cyclohexane, normal hexane, mixtures thereof etc. are mentioned.

--Styrene polymerization process--
As the first polymerization step, it is preferable to polymerize this by adding only the styrene monomer without adding isoprene in the presence of a catalyst. At this time, it is possible to adjust the molecular weight of the produced polymer or oligomer by appropriately selecting the amount of styrene monomer to be added and the reaction time.

  In the styrene polymerization step, the polymerization reaction is preferably performed in an atmosphere of an inert gas, preferably nitrogen gas or argon gas. The polymerization temperature of the polymerization reaction is not particularly limited, but is preferably in the range of −100 to 200 ° C., for example, and can be about room temperature. If the polymerization temperature is raised, the cis-1,4 selectivity of the polymerization reaction may be lowered. The pressure of the polymerization reaction is preferably in the range of 0.1 to 10.0 MPa in order to sufficiently incorporate styrene into the polymerization reaction system. The reaction time for the polymerization reaction is preferably in the range of 1 to 900 minutes for producing an oligomer having 10 or less styrene units, but can be appropriately selected depending on the conditions such as the type of catalyst and the polymerization temperature. In addition, when reaction temperature is 25-80 degreeC, it is preferable that reaction time shall be 5 to 300 minutes.

--Isoprene polymerization process--
As the second polymerization step, it is preferable to add an isoprene monomer to the styrene polymerization reaction product and to additionally polymerize the isoprene monomer into a styrene polymer or oligomer. In particular, when a catalyst described later is used, the copolymerization reaction easily shifts from styrene to isoprene due to its characteristics, so that a copolymer similar to a block copolymer is produced at a high rate.

  In the isoprene polymerization step, the polymerization reaction is preferably performed in an atmosphere of an inert gas, preferably nitrogen gas or argon gas. The polymerization temperature of the polymerization reaction is not particularly limited, but is preferably in the range of −100 ° C. to 200 ° C., for example, and can be about room temperature. If the polymerization temperature is raised, the cis-1,4 selectivity of the polymerization reaction may be lowered. The pressure of the polymerization reaction is preferably in the range of 0.1 to 10.0 MPa in order to sufficiently incorporate isoprene into the polymerization reaction system. The reaction time of the polymerization reaction is not particularly limited, and is preferably in the range of 1 second to 10 days, for example, but can be appropriately selected depending on conditions such as the type of catalyst and the polymerization temperature.

  In the isoprene polymerization step, the polymerization may be stopped using a polymerization terminator such as methanol, ethanol, isopropanol or the like.

--- Polymerization catalyst composition--
The above-mentioned polymerization process of styrene and isoprene is a process of polymerizing various monomers in the presence of the polymerization catalyst shown below, or the first polymerization catalyst composition, the second polymerization catalyst composition, or the third polymerization catalyst composition. Preferably including

--- First polymerization catalyst composition ---
The first polymerization catalyst composition (hereinafter also referred to as “first polymerization catalyst composition”) will be described.
As the first polymerization catalyst composition,
(A) component: a rare earth element compound or a reaction product of the rare earth element compound and a Lewis base, the rare earth element compound or the reaction product having no bond between the rare earth element and carbon,
Component (B): Contains ionic compound (B-1) composed of non-coordinating anion and cation, aluminoxane (B-2), Lewis acid, complex compound of metal halide and Lewis base, and active halogen. A polymerization catalyst composition containing at least one selected from the group consisting of at least one halogen compound (B-3) among organic compounds.
When the first polymerization catalyst composition contains at least one of the ionic compound (B-1) and the halogen compound (B-3), the polymerization catalyst composition further comprises:
(C) Component: The following general formula (X):
YR ¹ _a R ² _b R ³ _c (X)
(In the formula, Y is a metal selected from Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R1 and R2 are the same or different and are hydrocarbons having 1 to 10 carbon atoms. R ³ is a group or a hydrogen atom, and R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ may be the same as or different from R ¹ or R ^2, and Y is 1 in the periodic table. When the metal is selected from the group, a is 1, and b and c are 0, and when Y is the metal selected from groups 2 and 12 of the periodic table, a and In the case where b is 1 and c is 0, and Y is a metal selected from Group 13 of the Periodic Table, a, b and c are 1).

Since the ionic compound (B-1) and the halogen compound (B-3) do not have a carbon atom to be supplied to the component (A), the carbon source for the component (A) is the above ( Component C) is required. In addition, even if it is a case where the said polymerization catalyst composition contains the said aluminoxane (B-2), this polymerization catalyst composition can contain the said (C) component. The first polymerization catalyst composition may contain other components, such as a promoter, contained in a normal rare earth element compound-based polymerization catalyst composition.
In the polymerization reaction system, the concentration of the component (A) contained in the first polymerization catalyst composition is preferably in the range of 0.1 to 0.0001 mol / l.
Further, the polymerization catalyst composition preferably contains an additive D that can be an anionic ligand.

The component (A) used in the first polymerization catalyst composition is a rare earth element compound or a reaction product of the rare earth element compound and a Lewis base. Here, the reaction of the rare earth element compound and the rare earth element compound with the Lewis base is performed. The object does not have a bond between rare earth element and carbon. When the rare earth element compound and the reactant do not have a rare earth element-carbon bond, the compound is stable and easy to handle. Here, the rare earth element compound is a compound containing a lanthanoid element or scandium or yttrium composed of the elements of atomic numbers 57 to 71 in the periodic table.
Specific examples of the lanthanoid element include lanthanium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. In addition, the said (A) component may be used individually by 1 type, and may be used in combination of 2 or more type.

The rare earth element compound is preferably a divalent or trivalent salt or complex compound of a rare earth metal, and one or more coordinations selected from a hydrogen atom, a halogen atom and an organic compound residue. More preferably, the rare earth element compound contains a child. Furthermore, the reaction product of the rare earth element compound or the rare earth element compound and a Lewis base is represented by the following general formula (XI) or (XII):
M ¹¹ X ¹¹ ₂ · L ¹¹ w (XI)
M ¹¹ X ¹¹ ₃ · L ¹¹ w (XII)
(In the formula, M ¹¹ represents a lanthanoid element, scandium or yttrium, and X ¹¹ independently represents a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group, a silyl group, an aldehyde residue, a ketone residue. A group, a carboxylic acid residue, a thiocarboxylic acid residue or a phosphorus compound residue, L ¹¹ represents a Lewis base, and w represents 0 to 3).

  Specific examples of the group (ligand) bonded to the rare earth element of the rare earth element compound include a hydrogen atom; a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert- Aliphatic alkoxy groups such as butoxy group; phenoxy group, 2,6-di-tert-butylphenoxy group, 2,6-diisopropylphenoxy group, 2,6-dineopentylphenoxy group, 2-tert-butyl-6- Isopropylphenoxy group, 2-tert-butyl-6-neopentylphenoxy group, 2-isopropyl-6-neopentylphenoxy group; thiomethoxy group, thioethoxy group, thiopropoxy group, thio n-butoxy group, thioisobutoxy group, thio aliphatic thiolate groups such as sec-butoxy group and thio-tert-butoxy group; Noxy group, 2,6-di-tert-butylthiophenoxy group, 2,6-diisopropylthiophenoxy group, 2,6-dineopentylthiophenoxy group, 2-tert-butyl-6-isopropylthiophenoxy group, 2 Arylthiolate groups such as -tert-butyl-6-thioneopentylphenoxy, 2-isopropyl-6-thioneopentylphenoxy, 2,4,6-triisopropylthiophenoxy; dimethylamide, diethylamide, diisopropyl Aliphatic amide group such as amide group; phenylamide group, 2,6-di-tert-butylphenylamide group, 2,6-diisopropylphenylamide group, 2,6-dineopentylphenylamide group, 2-tert- Butyl-6-isopropylphenylamide group, 2-tert-butyl Arylamide groups such as ru-6-neopentylphenylamide group, 2-isopropyl-6-neopentylphenylamide group, 2,4,6-tert-butylphenylamide group; bistrialkylsilylamides such as bistrimethylsilylamide group Groups: silyl groups such as trimethylsilyl group, tris (trimethylsilyl) silyl group, bis (trimethylsilyl) methylsilyl group, trimethylsilyl (dimethyl) silyl group, triisopropylsilyl (bistrimethylsilyl) silyl group; fluorine atom, chlorine atom, bromine atom, iodine And halogen atoms such as atoms. Furthermore, residues of aldehydes such as salicylaldehyde, 2-hydroxy-1-naphthaldehyde, 2-hydroxy-3-naphthaldehyde; 2′-hydroxyacetophenone, 2′-hydroxybutyrophenone, 2′-hydroxypropiophenone, etc. Hydroxyphenone residues of: acetylacetone, benzoylacetone, propionylacetone, isobutylacetone, valerylacetone, ethylacetylacetone, etc. diketone residues; isovaleric acid, caprylic acid, octanoic acid, lauric acid, myristic acid, palmitic acid, Stearic acid, isostearic acid, oleic acid, linoleic acid, cyclopentanecarboxylic acid, naphthenic acid, ethylhexanoic acid, bivaric acid, versatic acid [trade name of Shell Chemical Co., Ltd., mixture of isomers of C10 monocarboxylic acid Synthetic acids comprised of, carboxylic acid residues such as phenylacetic acid, benzoic acid, 2-naphthoic acid, maleic acid, succinic acid; hexanethioic acid, 2,2-dimethylbutanethioic acid, decanethioic acid, thiobenzoic acid Thiocarboxylic acid residues such as: dibutyl phosphate, dipentyl phosphate, dihexyl phosphate, diheptyl phosphate, dioctyl phosphate, bis (2-ethylhexyl phosphate), bis (1-methylheptyl phosphate), dilauryl phosphate Dioleyl phosphate, diphenyl phosphate, bis (p-nonylphenyl) phosphate, bis (polyethylene glycol-p-nonylphenyl) phosphate, (butyl) phosphate (2-ethylhexyl), phosphoric acid (1-methylheptyl) ) (2-ethylhexyl), phosphoric acid esters such as phosphoric acid (2-ethylhexyl) (p-nonylphenyl) Residues; monobutyl 2-ethylhexylphosphonate, mono-2-ethylhexyl 2-ethylhexylphosphonate, mono-2-ethylhexyl phenylphosphonate, mono-p-nonylphenyl 2-ethylhexylphosphonate, mono-2-ethylhexyl phosphonate, Phosphonic acid ester residues such as mono-1-methylheptyl phosphonate, mono-p-nonylphenyl phosphonate, dibutylphosphinic acid, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, di Laurylphosphinic acid, dioleylphosphinic acid, diphenylphosphinic acid, bis (p-nonylphenyl) phosphinic acid, butyl (2-ethylhexyl) phosphinic acid, (2-ethylhexyl) (1-methylheptyl) phosphinic acid, (2-ethylhexyl) Phosphinic acids such as (p-nonylphenyl) phosphinic acid, butylphosphinic acid, 2-ethylhexylphosphinic acid, 1-methylheptylphosphinic acid, oleylphosphinic acid, laurylphosphinic acid, phenylphosphinic acid, p-nonylphenylphosphinic acid Can also be mentioned. In addition, these ligands may be used individually by 1 type, and may be used in combination of 2 or more type.

In the component (A) used in the first polymerization catalyst composition, examples of the Lewis base that reacts with the rare earth element compound include tetrahydrofuran, diethyl ether, dimethylaniline, trimethylphosphine, lithium chloride, neutral olefins, Diolefins and the like. Here, when the rare earth element compound reacts with a plurality of Lewis bases (in the formulas (XI) and (XII), when w is 2 or 3), the Lewis base L ¹¹ is the same or different. It may be.

Preferably, the rare earth element-containing compound preferably contains a compound represented by the following formula.
M- (NQ ¹ ) (NQ ² ) (NQ ³ ) (i)
(In the formula, M is at least one selected from lanthanoid, scandium and yttrium, and NQ ¹ , NQ ² and NQ ³ are amide groups, which may be the same or different, provided that M—N With bond)
That is, the compound represented by the above formula (i) has three MN bonds. Having three MN bonds has the advantage that the structure is stable because each bond is chemically equivalent and therefore easy to handle.

  In the above formula (i), examples of the amide group represented by NQ include aliphatic amide groups such as dimethylamide group, diethylamide group, diisopropylamide group; phenylamide group, 2,6-di-tert-butylphenylamide group, 2 , 6-diisopropylphenylamide group, 2,6-dineventylphenylamide group, 2-tert-butyl-6-isopropylphenylamide group, 2-tert-butyl-6-neobenzylphenylamide group, 2- An arylamide group such as isopropyl-6-neobutenylphenylamide group or 2,4,6-tert-butylphenylamide group; a bistrialkylsilylamide group such as bistrimethylsilylamide group may be used, but a bistrimethylsilylamide group Is preferred.

  The component (B) used in the first polymerization catalyst composition is at least one compound selected from the group consisting of an ionic compound (B-1), an aluminoxane (B-2), and a halogen compound (B-3). is there. In addition, it is preferable that content of the sum total of (B) component in said 1st polymerization catalyst composition is 0.1-50 times mole with respect to (A) component.

  The ionic compound represented by the above (B-1) is composed of a non-coordinating anion and a cation, and reacts with a reaction product of the rare earth element compound or its Lewis base as the component (A) to be cationic. Examples thereof include ionic compounds capable of generating a transition metal compound. Here, as the non-coordinating anion, for example, tetraphenyl borate, tetrakis (monofluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis ( Pentafluorophenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetra (tolyl) borate, tetra (xylyl) borate, (triphenyl, pentafluorophenyl) borate, [tris (pentafluorophenyl), phenyl] borate, tri Decahydride-7,8-dicarboundecaborate and the like can be mentioned. On the other hand, examples of the cation include a carbonium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation having a transition metal. Specific examples of the carbonium cation include trisubstituted carbonium cations such as triphenylcarbonium cation and tri (substituted phenyl) carbonium cation, and more specifically, as tri (substituted phenyl) carbonyl cation, Examples include tri (methylphenyl) carbonium cation, tri (dimethylphenyl) carbonium cation, and the like. Specific examples of ammonium cations include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, and tributylammonium cation (for example, tri (n-butyl) ammonium cation); N, N-dimethylanilinium N, N-dialkylanilinium cation such as cation, N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation; dialkylammonium cation such as diisopropylammonium cation and dicyclohexylammonium cation Is mentioned. Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri (methylphenyl) phosphonium cation, and tri (dimethylphenyl) phosphonium cation. Accordingly, the ionic compound is preferably a compound selected and combined from the above-mentioned non-coordinating anions and cations, specifically, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, triphenylcarbohydrate. Preferred is nitrotetrakis (pentafluorophenyl) borate. Moreover, these ionic compounds can be used individually by 1 type, or 2 or more types can be mixed and used for them. In addition, it is preferable that it is 0.1-10 times mol with respect to (A) component, and, as for content of the ionic compound in the said 1st polymerization catalyst composition, it is still more preferable that it is about 1 time mol.

  The aluminoxane represented by the above (B-2) is a compound obtained by bringing an organoaluminum compound and a condensing agent into contact with each other. For example, the repetition represented by the general formula: (—Al (R ′) O—) A chain aluminoxane or cyclic aluminoxane having a unit (wherein R ′ is a hydrocarbon group having 1 to 10 carbon atoms, and some of the hydrocarbon groups may be substituted with a halogen atom and / or an alkoxy group) The degree of polymerization of the unit is preferably 5 or more, and more preferably 10 or more. Here, specific examples of R ′ include a methyl group, an ethyl group, a propyl group, and an isobutyl group. Among these, a methyl group is preferable. Examples of the organoaluminum compound used as an aluminoxane raw material include trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, and mixtures thereof, and trimethylaluminum is particularly preferable. For example, an aluminoxane using a mixture of trimethylaluminum and tributylaluminum as a raw material can be preferably used. The content of the aluminoxane in the first polymerization catalyst composition is such that the element ratio Al / M of the rare earth element M constituting the component (A) and the aluminum element Al of the aluminoxane is about 10 to 1000. It is preferable to do.

  The halogen compound represented by (B-3) is composed of at least one of a Lewis acid, a complex compound of a metal halide and a Lewis base, and an organic compound containing an active halogen, and is, for example, the component (A). By reacting with a rare earth element compound or a reaction product thereof with a Lewis base, a cationic transition metal compound, a halogenated transition metal compound, or a compound in which the transition metal center is deficient in charge can be generated. In addition, it is preferable that content of the sum total of the halogen compound in said 1st polymerization catalyst composition is 1-5 times mole with respect to (A) component.

As the Lewis acid, boron-containing halogen compounds such as B (C ₆ F ₅ ) ₃ and aluminum-containing halogen compounds such as Al (C ₆ F ₅ ) ₃ can be used. A halogen compound containing an element belonging to the group V, VI or VIII can also be used. Preferably, aluminum halide or organometallic halide is used. Moreover, as a halogen element, chlorine or bromine is preferable. Specific examples of the Lewis acid include methyl aluminum dibromide, methyl aluminum dichloride, ethyl aluminum dibromide, ethyl aluminum dichloride, butyl aluminum dibromide, butyl aluminum dichloride, dimethyl aluminum bromide, dimethyl aluminum chloride, diethyl aluminum bromide, diethyl Aluminum chloride, dibutylaluminum bromide, dibutylaluminum chloride, methylaluminum sesquibromide, methylaluminum sesquichloride, ethylaluminum sesquibromide, ethylaluminum sesquichloride, dibutyltin dichloride, aluminum tribromide, antimony trichloride, antimony pentachloride, phosphorus trichloride , Pentachloride , Tin tetrachloride, titanium tetrachloride, tungsten hexachloride, etc., among which diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum bromide, ethylaluminum sesquibromide, ethylaluminum dibromide preferable.

  The metal halide constituting the complex compound of the above metal halide and Lewis base includes beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, iodine. Calcium chloride, barium chloride, barium bromide, barium iodide, zinc chloride, zinc bromide, zinc iodide, cadmium chloride, cadmium bromide, cadmium iodide, mercury chloride, mercury bromide, mercury iodide, manganese chloride, Manganese bromide, manganese iodide, rhenium chloride, rhenium bromide, rhenium iodide, copper chloride, copper iodide, silver chloride, silver bromide, silver iodide, gold chloride, gold iodide, gold bromide, etc. Of these, magnesium chloride, calcium chloride, barium chloride, manganese chloride, zinc chloride, and copper chloride are preferred. , Magnesium chloride, manganese chloride, zinc chloride, copper chloride being particularly preferred.

  Moreover, as a Lewis base which comprises the complex compound of the said metal halide and a Lewis base, a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, alcohol, etc. are preferable. Specifically, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, triethylphosphine, tributylphosphine, triphenylphosphine, diethylphosphinoethane, diphenylphosphinoethane, acetylacetone, benzoylacetone , Propionitrile acetone, valeryl acetone, ethyl acetylacetone, methyl acetoacetate, ethyl acetoacetate, phenyl acetoacetate, dimethyl malonate, diethyl malonate, diphenyl malonate, acetic acid, octanoic acid, 2-ethyl-hexanoic acid, olein Acid, stearic acid, benzoic acid, naphthenic acid, versatic acid, triethylamine, N, N-dimethylacetamide, tetrahydrofuran, diphenyl ether, 2-ethyl-hexyl alcohol Examples include oleyl alcohol, stearyl alcohol, phenol, benzyl alcohol, 1-decanol, and lauryl alcohol. Among these, tri-2-ethylhexyl phosphate, tricresyl phosphate, acetylacetone, 2-ethylhexanoic acid, versatic acid, 2 -Ethylhexyl alcohol, 1-decanol and lauryl alcohol are preferred.

  The Lewis base is reacted at a ratio of 0.01 to 30 mol, preferably 0.5 to 10 mol, per 1 mol of the metal halide. When the reaction product with the Lewis base is used, the metal remaining in the polymer can be reduced.

  Examples of the organic compound containing the active halogen include benzyl chloride.

The component (C) used in the first polymerization catalyst composition is the above general formula (X):
YR ¹ _a R ² _b R ³ _c (X)
(In the formula, Y is a metal selected from Group 1, Group 2, Group 12, and Group 13 of the Periodic Table, and R ¹ and R ² are the same or different and have 1 to 10 carbon atoms. R ³ is a hydrocarbon group or a hydrogen atom, and R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ may be the same as or different from R ¹ or R ^2, and Y is a periodic table. When it is a metal selected from Group 1, a is 1 and b and c are 0, and when Y is a metal selected from Groups 2 and 12 of the Periodic Table, a and b are 1 and c is 0, and when Y is a metal selected from Group 13 of the Periodic Table, a, b and c are 1). Yes, the following general formula (Xa):
AlR ¹ R ² R ³ (Xa)
[Wherein, R ¹ and R ² are the same or different and each represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ represents the above It may be the same as or different from R ¹ or R ² ]. Examples of the organoaluminum compound represented by the general formula (Xa) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, and tripentylaluminum. , Trihexyl aluminum, tricyclohexyl aluminum, trioctyl aluminum; diethyl aluminum hydride, di-n-propyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, dihexyl aluminum hydride, diiso hydrogenated Hexyl aluminum, dioctyl aluminum hydride, diisooctyl aluminum hydride; ethyl aluminum dihydride, n-propyl aluminum Um dihydride, include isobutyl aluminum dihydride and the like, among these, triethylaluminum, triisobutylaluminum, hydrogenated diethylaluminum, hydrogenated diisobutylaluminum are preferred. The organoaluminum compound as component (C) described above can be used alone or in combination of two or more. In addition, it is preferable that it is 1-50 times mole with respect to (A) component, and, as for content of the organoaluminum compound in the said 1st polymerization catalyst composition, it is still more preferable that it is about 10 times mole.

Addition of the additive D that can be an anionic ligand is preferable because it produces an effect that a synthetic polyisoprene having a higher cis-1,4 bond amount can be synthesized in a high yield.
The additive D is not particularly limited as long as it can be exchanged with the amide group of the component (A), but preferably has any one of an OH group, an NH group, and an SH group.

Specific examples of the compound having an OH group include aliphatic alcohols and aromatic alcohols. Specifically, 2-ethyl-1-hexanol, dibutylhydroxytoluene, alkylated phenol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol), 4,4′-butylidenebis- (6- t-butyl-3-methylphenol), 2,2'-methylenebis- (4-methyl-6-t-butylphenol), 2,2'-methylenebis- (4-ethyl-6-t-butylphenol), 2, 6-di-t-4-ethylphenol, 1,1,3-tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane, n-octadecyl-3- (4-hydroxy-3, 5-di-t-butylphenyl) propionate, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, dilauryl thiol Examples include, but are not limited to, odipropionate, distearyl thiodipropionate, and dimyristyl thiopropionate. For example, as a hindered phenol type, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3 5-triazine, pentaerythryl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N′-he Xamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3,5-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5- Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, octyl Diphenylamine, 2,4-bis [(octylthio) methyl] -o-cresol, and the like.
Moreover, N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine can be given as a hydrazine system.

  Examples of those having an NH group include primary amines and secondary amines such as alkylamines and arylamines. Specific examples include dimethylamine, diethylamine, pyrrole, ethanolamine, diethanolamine, dicyclohexylamine, N, N′-dibenzylethylenediamine, bis (2-diphenylphosphinophenyl) amine, and the like.

（式中、Ｒ¹、Ｒ²及びＲ³はそれぞれ独立して−Ｏ−Ｃ_jＨ_2j+1、−（Ｏ−Ｃ_kＨ_2k−）_a −Ｏ−Ｃ_mＨ_2m+1又は−Ｃ_nＨ_2n+1 で表され、Ｒ¹、Ｒ²及びＲ³の少なくとも１つが−（Ｏ−Ｃ_kＨ_2k−）_a −Ｏ−Ｃ_mＨ_2m+1であり、ｊ、ｍ及びｎはそれぞれ独立して０〜１２であり、ｋ及びａはそれぞれ独立して１〜１２であり、Ｒ⁴は炭素数１〜１２であって、直鎖、分岐、もしくは環状の、飽和もしくは不飽和の、アルキレン基、シクロアルキレン基、シクロアルキルアルキレン基、シクロアルケニルアルキレン基、アルケニレン基、シクロアルケニレン基、シクロアルキルアルケニレン基、シクロアルケニルアルケニレン基、アリーレン基又はアラルキレン基である。）
一般式(Ｉ)で示されるものの具体例として、３−メルカプトプロピルトリメトキシシラン、３−メルカプトプロピルトリエトキシシラン、３−メルカプトプロピルメチルジメトキシシラン、（メルカプトメチル）ジメチルエトキシシラン、（メルカプトメチル）ジメチルエトキシシラン、メルカプトメチルトリメトキシシラン等が挙げられる。

（式中、Ｗは−ＮＲ⁸−、−Ｏ−又は−ＣＲ⁹Ｒ¹⁰−（ここで、Ｒ⁸及びＲ⁹は−Ｃ_pＨ_2p+1であり、Ｒ¹⁰は−Ｃ_qＨ_2q+1であり、ｐ及びｑはそれぞれ独立して０〜２０である。）で表され、Ｒ⁵及びＲ⁶はそれぞれ独立して−Ｍ−Ｃ_rＨ_2r−（ここで、Ｍは−Ｏ−又は−ＣＨ₂−であり、ｒは１〜２０である。）で表され、Ｒ⁷は−Ｏ−Ｃ_jＨ_2j+1、−（Ｏ−Ｃ_kＨ_2k−）_a −Ｏ−Ｃ_mＨ_2m+1又は−Ｃ_nＨ_2n+1 で表され、ｊ、ｍ及びｎはそれぞれ独立して０〜１２であり、ｋ及びａはそれぞれ独立して１〜１２であり、Ｒ⁴は炭素数１〜１２であって、直鎖、分岐、もしくは環状の、飽和もしくは不飽和の、アルキレン基、シクロアルキレン基、シクロアルキルアルキレン基、シクロアルケニルアルキレン基、アルケニレン基、シクロアルケニレン基、シクロアルキルアルケニレン基、シクロアルケニルアルケニレン基、アリーレン基又はアラルキレン基である。）一般式(ＩＩ)で示されるものの具体例として、３−メルカプトプロピル（エトキシ）−１，３−ジオキサ−６−メチルアザ−２−シラシクロオクタン、３−メルカプトプロピル（エトキシ）−１，３−ジオキサ−６−ブチルアザ−２−シラシクロオクタン、３−メルカプトプロピル（エトキシ）−１，３−ジオキサ−６−ドデシルアザ−２−シラシクロオクタンなどが挙げられる。 Examples of those having an SH group include aliphatic thiols, aromatic thiols and the like, and compounds represented by the following general formulas (I) and (II).

Wherein R ¹ , R ² and R ³ are each independently —O—C _j H _{2j + 1} , — (O—C _k H _2k —) _a —O—C _m H _{2m + 1} or —C _n H _{2n + 1} , wherein at least one of R ¹ , R ² and R ³ is — (O—C _k H _2k −) _a —O—C _m H _{2m + 1} , j, m and n are Each independently 0 to 12, k and a each independently 1 to 12, R ⁴ has 1 to 12 carbon atoms, straight, branched or cyclic, saturated or unsaturated An alkylene group, a cycloalkylene group, a cycloalkylalkylene group, a cycloalkenylalkylene group, an alkenylene group, a cycloalkenylene group, a cycloalkylalkenylene group, a cycloalkenylalkenylene group, an arylene group, or an aralkylene group.
Specific examples of those represented by the general formula (I) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, (mercaptomethyl) dimethylethoxysilane, and (mercaptomethyl) dimethyl. Examples thereof include ethoxysilane and mercaptomethyltrimethoxysilane.

(Wherein, W is —NR ⁸ —, —O— or —CR ⁹ R ¹⁰ — (wherein R ⁸ and R ⁹ are —C _p H _{2p + 1} , R ¹⁰ is —C _q H _{2q + 1} and p and q are each independently 0 to 20, and R ⁵ and R ⁶ are each independently —M—C _r H _2r — (where M is —O— Or —CH ₂ — and r is 1 to 20.), and R ⁷ is —O—C _j H _{2j + 1} , — (O—C _k H _2k —) _a —O—C _m. H _{2m + 1} or —C _n H _{2n + 1} , j, m and n are each independently 0 to 12, k and a are each independently 1 to 12, and R ⁴ is carbon. A linear, branched, or cyclic, saturated or unsaturated alkylene group, cycloalkylene group, cycloalkylalkylene group, cycloalkenylalkylene group, alkenylene group, cycloalkenyl group Group, cycloalkylalkenylene group, cycloalkenylalkenylene group, arylene group or aralkylene group.) As a specific example of the compound represented by the general formula (II), 3-mercaptopropyl (ethoxy) -1,3-dioxa-6 -Methylaza-2-silacyclooctane, 3-mercaptopropyl (ethoxy) -1,3-dioxa-6-butylaza-2-silacyclooctane, 3-mercaptopropyl (ethoxy) -1,3-dioxa-6-dodecylaza -2-silacyclooctane and the like.

As the additive D, an anionic tridentate ligand precursor represented by the following general formula (ii) can be preferably used.
^{E 1 -T 1 -X-T 2} -E 2 ··· (ii)
(X represents an anionic electron donating group containing a coordinating atom selected from Group 15 atoms, and E ¹ and E ² are each independently a coordinating atom selected from Group 15 and Group 16 atoms. And T ¹ and T ² are each a cross-linking group that cross-links X, E ^1, and ~ E ² )

  Additive D is preferably added in an amount of 0.01 to 10 mol, particularly 0.1 to 1.2 mol, with respect to 1 mol of the rare earth element compound. When the addition amount is less than 0.1 mol, the polymerization of the monomer does not proceed sufficiently, and it becomes difficult to achieve the object of the present invention. The addition amount is preferably equivalent (1.0 mol) to the rare earth element-prevented material, but an excessive amount may be added. However, if the addition amount exceeds 1.2 mol, the loss of the reagent is large, which is not preferable.

In the general formula (ii), the neutral electron donating groups E ¹ and E ² are groups containing a coordinating atom selected from Group 15 and Group 16. E ¹ and ~ E ² may be the same group or different groups. Examples of the coordinating atom include nitrogen N, phosphorus P, oxygen O, sulfur S and the like, preferably P.

When the coordination atom contained in E ¹ and E ² is P, the neutral electron donating group E ¹ or E ² is 1) a diaryl phosphino group such as a diphenylphosphino group or a ditolylphosphino group. 2) Dialkylphosphino groups such as dimethylphosphino group and diethylphosphino group 3) Alkylarylphosphino groups such as methylphenylphosphino group are exemplified, more preferably diarylphosphino groups are exemplified. .

When the coordination atom contained in E ¹ and E ² is N, examples of the neutral electron donating group E ¹ or E ² include 1) dimethylamino group, diethylamino group, bis (trimethylsilyl) amino group, and the like 2) diarylamino groups such as diphenylamino group, and 3) alkylarylamino groups such as methylphenyl group.

When the coordination atom contained in E ¹ and E ² is O, the neutral electron donating group E ¹ or E ² is 1) alkoxy such as methoxy group, ethoxy group, propoxy group, butoxy group Group, 2) aryloxy group such as phenoxy group, 2,6-dimethylphenoxy group and the like.

When the coordination atom contained in E ¹ and E ² is S, the neutral electron donating group E ¹ or E ² is 1) alkylthio such as methylthio group, ethylthio group, propylthio group, butylthio group, etc. Group, 2) arylthio group such as phenylthio group and tolylthio group.

  The anionic electron donating group X is a group containing a coordination atom selected from Group 15. The coordination atom is preferably phosphorus P or nitrogen N, more preferably N.

The bridging groups T ¹ and T ² may be any group that can cross-link X, E ^1, and E ² , and examples thereof include an arylene group that may have a substituent on the aryl ring. T ¹ and T ² may be the same group or different groups.
The arylene group may be a phenylene group, a naphthylene group, a pyridylene group, a thienylene group (preferably a phenylene group or a naphthylene group), or the like. Any group may be substituted on the aryl ring of the arylene group. Examples of the substituent include alkyl groups such as methyl group and ethyl group, aryl groups such as phenyl group and tolyl group, halogen groups such as fluoro, chloro and bromo, and silyl groups such as trimethylsilyl group.
More preferred examples of the arylene group include a 1,2-phenylene group.

  The anionic tridentate ligand precursor in the metal complex constituting the polymerization catalyst can be produced with reference to, for example, Organometallics, 23, p 4778-4787 (2004). More specifically, a bis (2-diphenylphosphinophenyl) amine (PNP) ligand is mentioned.

（式中、Ｍは、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^Rは、それぞれ独立して無置換もしくは置換インデニルを示し、Ｒ^a〜Ｒ^fは、それぞれ独立して炭素数１〜３のアルキル基又は水素原子を示し、Ｌは、中性ルイス塩基を示し、ｗは、０〜３の整数を示す）で表されるメタロセン錯体、及び下記一般式（ＩＶ）： --- Second polymerization catalyst composition ---
Next, the second polymerization catalyst composition (hereinafter also referred to as “second polymerization catalyst composition”) will be described. As the second polymerization catalyst composition, the following general formula (III):

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^R independently represents unsubstituted or substituted indenyl, and R ^{a to} R ^f each independently represents an alkyl having 1 to 3 carbon atoms. A group or a hydrogen atom, L represents a neutral Lewis base, w represents an integer of 0 to 3), and the following general formula (IV):

（式中、Ｍは、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^Rは、それぞれ独立して無置換もしくは置換インデニルを示し、Ｘ'は、水素原子、ハロゲン原子、アルコキシド基、チオラート基、アミド基、シリル基又は炭素数１〜２０の炭化水素基を示し、Ｌは、中性ルイス塩基を示し、ｗは、０〜３の整数を示す）で表されるメタロセン錯体、並びに下記一般式（Ｖ）：

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^R each independently represents an unsubstituted or substituted indenyl group, and X ′ represents a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group. , A silyl group or a hydrocarbon group having 1 to 20 carbon atoms, L represents a neutral Lewis base, w represents an integer of 0 to 3, and the following general formula (V ):

（式中、Ｍは、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^R'は、無置換もしくは置換シクロペンタジエニル、インデニル又はフルオレニルを示し、Ｘは、水素原子、ハロゲン原子、アルコキシド基、チオラート基、アミド基、シリル基又は炭素数１〜２０の炭化水素基を示し、Ｌは、中性ルイス塩基を示し、ｗは、０〜３の整数を示し、［Ｂ］^-は、非配位性アニオンを示す）で表されるハーフメタロセンカチオン錯体からなる群より選択される少なくとも１種類の錯体を含む重合触媒組成物が挙げられる。

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^{R ′} represents unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl, and X represents a hydrogen atom, a halogen atom, an alkoxide group or a thiolate group. , An amide group, a silyl group, or a hydrocarbon group having 1 to 20 carbon atoms, L represents a neutral Lewis base, w represents an integer of 0 to 3, and [B] ⁻ represents a non-coordinating group. A polymerization catalyst composition containing at least one complex selected from the group consisting of a half metallocene cation complex represented by

The second polymerization catalyst composition may further contain other components contained in the polymerization catalyst composition containing a normal metallocene complex, such as a promoter. Here, the metallocene complex is a complex compound in which one or more cyclopentadienyl or a derivative thereof is bonded to a central metal, and in particular, one cyclopentadienyl or a derivative thereof bonded to the central metal. A certain metallocene complex may be called a half metallocene complex.
In the polymerization reaction system, the concentration of the complex contained in the second polymerization catalyst composition is preferably in the range of 0.1 to 0.0001 mol / L.

In the metallocene complexes represented by the above general formula (III) and formula (IV), Cp ^R in the formula is unsubstituted indenyl or substituted indenyl. Cp ^R having an indenyl ring as a basic skeleton can be represented by C ₉ H _7-X R _X or C ₉ H _11-X R _X. Here, X is an integer of 0-7 or 0-11. In addition, each R is preferably independently a hydrocarbyl group or a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group. Specific examples of the substituted indenyl include 2-phenylindenyl and 2-methylindenyl. In addition, two Cp ^R in general formula (III) and formula (IV) may be mutually the same or different.

In the half metallocene cation complex represented by the general formula (V), Cp ^{R ′} in the formula is unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl. Among these, unsubstituted or substituted indenyl It is preferable that Cp ^{R ′} having a cyclopentadienyl ring as a basic skeleton is represented by C ₅ H _5-X R _X. Here, X is an integer of 0-5. In addition, each R is preferably independently a hydrocarbyl group or a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group. Specific examples of Cp ^{R ′} having a cyclopentadienyl ring as a basic skeleton include the following.

（式中、Ｒは水素原子、メチル基又はエチル基を示す。）
一般式（Ｖ）において、上記インデニル環を基本骨格とするＣｐ^R'は、一般式（ＩＩＩ）のＣｐ^Rと同様に定義され、好ましい例も同様である。

(In the formula, R represents a hydrogen atom, a methyl group or an ethyl group.)
In the general formula (V), Cp ^{R ′} having the above indenyl ring as a basic skeleton is defined in the same manner as Cp ^{R in the} general formula (III), and preferred examples thereof are also the same.

In the general formula (V), Cp ^{R ′} having the fluorenyl ring as a basic skeleton can be represented by C ₁₃ H _9-X R _X or C ₁₃ H _17-X R _X. Here, X is an integer of 0-9 or 0-17. In addition, each R is preferably independently a hydrocarbyl group or a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group.

  The central metal M in the general formulas (III), (IV), and (V) is a lanthanoid element, scandium, or yttrium. The lanthanoid elements include 15 elements having atomic numbers 57 to 71, and any of these may be used. Preferred examples of the central metal M include samarium Sm, neodymium Nd, praseodymium Pr, gadolinium Gd, cerium Ce, holmium Ho, scandium Sc, and yttrium Y.

The metallocene complex represented by the general formula (III) includes a silylamide ligand [—N (SiR ₃ ) ₂ ]. The R groups contained in the silylamide ligand (R ^{a to} R ^f in the general formula (III)) are each independently an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. Moreover, it is preferable that at least one of R ^{a to} R ^f is a hydrogen atom. By making at least one of R ^{a to} R ^f a hydrogen atom, the synthesis of the catalyst is facilitated, and the bulk height around silicon is reduced, so that non-conjugated olefin is easily introduced. From the same viewpoint, it is more preferable that at least one of R ^{a to} R ^c is a hydrogen atom and at least one of R ^{d to} R ^f is a hydrogen atom. Furthermore, a methyl group is preferable as the alkyl group.

The metallocene complex represented by the general formula (IV) includes a silyl ligand [—SiX ′ ₃ ]. X ′ contained in the silyl ligand [—SiX ′ ₃ ] is a group defined in the same manner as X in the general formula (V) described below, and preferred groups are also the same.

  In the general formula (V), X is a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group, a silyl group, and a hydrocarbon group having 1 to 20 carbon atoms. Here, examples of the alkoxide group include aliphatic alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group; a phenoxy group and 2,6-dioxy -Tert-butylphenoxy group, 2,6-diisopropylphenoxy group, 2,6-dinepentylphenoxy group, 2-tert-butyl-6-isopropylphenoxy group, 2-tert-butyl-6-neopentylphenoxy group, Examples include aryloxide groups such as 2-isopropyl-6-neopentylphenoxy group, and among these, 2,6-di-tert-butylphenoxy group is preferable.

  In the general formula (V), the thiolate group represented by X includes a thiomethoxy group, a thioethoxy group, a thiopropoxy group, a thio n-butoxy group, a thioisobutoxy group, a thiosec-butoxy group, a thiotert-butoxy group and the like Group thiolate group; thiophenoxy group, 2,6-di-tert-butylthiophenoxy group, 2,6-diisopropylthiophenoxy group, 2,6-dineopentylthiophenoxy group, 2-tert-butyl-6-isopropyl Arylthiolate groups such as thiophenoxy group, 2-tert-butyl-6-thioneopentylphenoxy group, 2-isopropyl-6-thioneopentylphenoxy group, 2,4,6-triisopropylthiophenoxy group, etc. Of these, 2,4,6-triisopropylthiophenoxy group is preferred. Arbitrariness.

  In the general formula (IV), examples of the amide group represented by X include aliphatic amide groups such as dimethylamide group, diethylamide group, and diisopropylamide group; phenylamide group, 2,6-di-tert-butylphenylamide group, 2 , 6-diisopropylphenylamide group, 2,6-dineopentylphenylamide group, 2-tert-butyl-6-isopropylphenylamide group, 2-tert-butyl-6-neopentylphenylamide group, 2-isopropyl- Arylamide groups such as 6-neopentylphenylamide group and 2,4,6-tri-tert-butylphenylamide group; and bistrialkylsilylamide groups such as bistrimethylsilylamide group. Among these, bistrimethylsilylamide Groups are preferred.

  In the general formula (V), examples of the silyl group represented by X include trimethylsilyl group, tris (trimethylsilyl) silyl group, bis (trimethylsilyl) methylsilyl group, trimethylsilyl (dimethyl) silyl group, triisopropylsilyl (bistrimethylsilyl) silyl group, and the like. Among these, a tris (trimethylsilyl) silyl group is preferable.

  In the general formula (V), the halogen atom represented by X may be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, but a chlorine atom or a bromine atom is preferred. Moreover, as a C1-C20 hydrocarbon group which X represents, specifically, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert- Linear or branched aliphatic hydrocarbon groups such as butyl group, neopentyl group, hexyl group, octyl group; aromatic hydrocarbon groups such as phenyl group, tolyl group, naphthyl group; aralkyl groups such as benzyl group, etc. Others: Examples include hydrocarbon groups containing silicon atoms such as trimethylsilylmethyl group and bistrimethylsilylmethyl group. Among these, methyl group, ethyl group, isobutyl group, trimethylsilylmethyl group and the like are preferable.

  In the general formula (V), X is preferably a bistrimethylsilylamide group or a hydrocarbon group having 1 to 20 carbon atoms.

In formula (V), [B] ^- The non-coordinating anion represented by, for example, a tetravalent boron anion. Specific examples of the tetravalent boron anion include tetraphenyl borate, tetrakis (monofluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis ( Pentafluorophenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetra (tolyl) borate, tetra (xylyl) borate, (triphenyl, pentafluorophenyl) borate, [tris (pentafluorophenyl), phenyl] borate, tri Decahydride-7,8-dicarbaoundecaborate and the like can be mentioned, and among these, tetrakis (pentafluorophenyl) borate is preferable.

  The metallocene complex represented by the general formulas (III) and (IV) and the half metallocene cation complex represented by the general formula (V) are further 0 to 3, preferably 0 to 1 neutral. Contains Lewis base L. Here, examples of the neutral Lewis base L include tetrahydrofuran, diethyl ether, dimethylaniline, trimethylphosphine, lithium chloride, neutral olefins, neutral diolefins, and the like. Here, when the complex includes a plurality of neutral Lewis bases L, the neutral Lewis bases L may be the same or different.

  Moreover, the metallocene complex represented by the general formula (III) and the formula (IV) and the half metallocene cation complex represented by the general formula (V) may exist as a monomer, It may exist as a body or higher multimer.

（式中、Ｘ''はハライドを示す。）
上記一般式（ＩＶ）で表されるメタロセン錯体は、例えば、溶媒中でランタノイドトリスハライド、スカンジウムトリスハライド又はイットリウムトリスハライドを、インデニルの塩（例えばカリウム塩やリチウム塩）及びシリルの塩（例えばカリウム塩やリチウム塩）と反応させることで得ることができる。なお、反応温度は室温程度にすればよいので、温和な条件で製造することができる。また、反応時間は任意であるが、数時間〜数十時間程度である。反応溶媒は特に限定されないが、原料及び生成物を溶解する溶媒であることが好ましく、例えばトルエンを用いればよい。以下に、一般式（ＩＶ）で表されるメタロセン錯体を得るための反応例を示す。 The metallocene complex represented by the general formula (III) includes, for example, a lanthanide trishalide, scandium trishalide or yttrium trishalide in a solvent, an indenyl salt (for example, potassium salt or lithium salt) and bis (trialkylsilyl). It can be obtained by reacting with an amide salt (for example, potassium salt or lithium salt). In addition, since reaction temperature should just be about room temperature, it can manufacture on mild conditions. The reaction time is arbitrary, but is about several hours to several tens of hours. The reaction solvent is not particularly limited, but is preferably a solvent that dissolves the raw material and the product. For example, toluene may be used. Below, the reaction example for obtaining the metallocene complex represented by general formula (III) is shown.

(In the formula, X ″ represents a halide.)
The metallocene complex represented by the general formula (IV) includes, for example, a lanthanoid trishalide, a scandium trishalide, or an yttrium trishalide in a solvent, an indenyl salt (for example, potassium salt or lithium salt), and a silyl salt (for example, potassium). Salt or lithium salt). In addition, since reaction temperature should just be about room temperature, it can manufacture on mild conditions. The reaction time is arbitrary, but is about several hours to several tens of hours. The reaction solvent is not particularly limited, but is preferably a solvent that dissolves the raw material and the product. For example, toluene may be used. Below, the example of reaction for obtaining the metallocene complex represented by general formula (IV) is shown.

（式中、Ｘ''はハライドを示す。）

(In the formula, X ″ represents a halide.)

  The half metallocene cation complex represented by the general formula (V) can be obtained, for example, by the following reaction.

Here, in the compound represented by the general formula (VI), M represents a lanthanoid element, scandium or yttrium, and Cp ^{R ′} independently represents unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl. , X represents a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group, a silyl group, or a hydrocarbon group having 1 to 20 carbon atoms, L represents a neutral Lewis base, and w represents 0 to 3 Indicates an integer. In the ionic compound represented by the general formula [A] ⁺ [B] ⁻ , [A] ⁺ represents a cation, and [B] ⁻ represents a non-coordinating anion.

Examples of the cation represented by [A] ⁺ include a carbonium cation, an oxonium cation, an amine cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation having a transition metal. Examples of the carbonium cation include trisubstituted carbonium cations such as a triphenylcarbonium cation and a tri (substituted phenyl) carbonium cation. The tri (substituted phenyl) carbonyl cation is specifically exemplified by tri (methylphenyl). ) Carbonium cation and the like. Examples of amine cations include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, and tributylammonium cation; N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N- N, N-dialkylanilinium cations such as 2,4,6-pentamethylanilinium cation; dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation. Examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri (methylphenyl) phosphonium cation, and tri (dimethylphenyl) phosphonium cation. Among these cations, N, N-dialkylanilinium cation or carbonium cation is preferable, and N, N-dialkylanilinium cation is particularly preferable.

The ionic compound represented by the general formula [A] ⁺ [B] ⁻ used for the above reaction is a compound selected and combined from the above non-coordinating anions and cations, which is N, N-dimethylaniline. Preference is given to nium tetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis (pentafluorophenyl) borate and the like. In addition, the ionic compound represented by the general formula [A] + [B]-is preferably added in an amount of 0.1 to 10 times mol, more preferably about 1 time mol based on the metallocene complex. When the half metallocene cation complex represented by the general formula (V) is used for the polymerization reaction, the half metallocene cation complex represented by the general formula (V) may be provided as it is in the polymerization reaction system, or the compound represented by the general formula (IV) and the general formula used in the reaction [a] ⁺ [B] ^- provides an ionic compound represented separately into the polymerization reaction system, the general formula in the reaction system (V You may form the half metallocene cation complex represented by this. Further, by using a combination of the metallocene complex represented by the general formula (III) or the formula (IV) and the ionic compound represented by the general formula [A] ⁺ [B] ^- A half metallocene cation complex represented by the formula (V) can also be formed.

  The structures of the metallocene complexes represented by the general formulas (III) and (IV) and the half metallocene cation complex represented by the general formula (V) are preferably determined by X-ray structural analysis.

  The co-catalyst that can be used in the second polymerization catalyst composition can be arbitrarily selected from components used as a co-catalyst for a polymerization catalyst composition containing a normal metallocene complex. Suitable examples of the cocatalyst include aluminoxanes, organoaluminum compounds, and the above ionic compounds. These promoters may be used alone or in combination of two or more.

  The aluminoxane is preferably an alkylaminoxan, and examples thereof include methylaluminoxane (MAO) and modified methylaluminoxane. As the modified methylaluminoxane, MMAO-3A (manufactured by Tosoh Finechem Co., Ltd.) and the like are preferable. The aluminoxane content in the second polymerization catalyst composition is such that the element ratio Al / M between the central metal M of the metallocene complex and the aluminum element Al of the aluminoxane is about 10 to 1000, preferably about 100. It is preferable to make it.

  On the other hand, as the organoaluminum compound, the general formula AlRR′R ″ (wherein R and R ′ are each independently a C1-C10 hydrocarbon group or a hydrogen atom, and R ″ is a C1-C10 An organoaluminum compound represented by (a hydrocarbon group) is preferable. Examples of the organoaluminum compound include trialkylaluminum, dialkylaluminum chloride, alkylaluminum dichloride, and dialkylaluminum hydride. Among these, trialkylaluminum is preferable. Examples of the trialkylaluminum include triethylaluminum and triisobutylaluminum. In addition, it is preferable that it is 1-50 times mol with respect to a metallocene complex, and, as for content of the organoaluminum compound in the said polymerization catalyst composition, it is still more preferable that it is about 10 times mol.

  Further, in the polymerization catalyst composition, the metallocene complex represented by the general formula (III) and the formula (IV) and the half metallocene cation complex represented by the general formula (V) are respectively used as appropriate promoters. By combining, the amount of cis-1,4 bonds and the molecular weight of the resulting polymer can be increased.

--- Third polymerization catalyst composition ---
Next, a third polymerization catalyst composition (hereinafter also referred to as “third polymerization catalyst composition”) will be described.
The third polymerization catalyst composition has the following formula (A) as a rare earth element-containing compound:
R _a MX _b QY _b (A)
(In the formula, each R independently represents unsubstituted or substituted indenyl, the R is coordinated to M, M represents a lanthanoid element, scandium or yttrium, and each X independently represents 1 to 1 carbon atoms. 20 represents a hydrocarbon group, X is μ-coordinated to M and Q, Q represents a group 13 element of the periodic table, and Y independently represents a hydrocarbon group having 1 to 20 carbon atoms or A hydrogen atom, wherein Y is coordinated to Q, and a and b are 2).

（式中、Ｍ¹は、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^Rは、それぞれ独立して無置換もしくは置換インデニルを示し、Ｒ^A及びＲ^Bは、それぞれ独立して炭素数１〜２０の炭化水素基を示し、該Ｒ^A及びＲ^Bは、Ｍ¹及びＡｌにμ配位しており、Ｒ^C及びＲ^Dは、それぞれ独立して炭素数１〜２０の炭化水素基又は水素原子を示す）で表されるメタロセン系複合触媒が挙げられる。
上記メタロセン系重合触媒を用いることで、重合体を製造することができる。また、上記メタロセン系複合触媒、例えば予めアルミニウム触媒と複合させてなる触媒を用いることで、重合体合成時に使用されるアルキルアルミニウムの量を低減したり、無くしたりすることが可能となる。なお、従来の触媒系を用いると、重合体合成時に大量のアルキルアルミニウムを用いる必要がある。例えば、従来の触媒系では、金属触媒に対して１０当量以上のアルキルアルミニウムを用いる必要があるところ、上記メタロセン系複合触媒であれば、５当量程度のアルキルアルミニウムを加えることで、優れた触媒作用が発揮される。 In a preferred example of the metallocene composite catalyst, the following formula (XV):

(In the formula, M ¹ represents a lanthanoid element, scandium or yttrium, Cp ^R independently represents an unsubstituted or substituted indenyl group, and R ^A and R ^B each independently have 1 to 20 carbon atoms. R ^A and R ^B are μ-coordinated to M ¹ and Al, and R ^C and R ^D each independently represent a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. Metallocene-based composite catalysts represented by
A polymer can be produced by using the metallocene polymerization catalyst. In addition, by using the above metallocene composite catalyst, for example, a catalyst previously combined with an aluminum catalyst, the amount of alkylaluminum used during the synthesis of the polymer can be reduced or eliminated. If a conventional catalyst system is used, it is necessary to use a large amount of alkylaluminum at the time of polymer synthesis. For example, in the conventional catalyst system, it is necessary to use 10 equivalents or more of alkylaluminum with respect to the metal catalyst. If the metallocene composite catalyst is used, an excellent catalytic action can be obtained by adding about 5 equivalents of alkylaluminum. Is demonstrated.

  In the metallocene composite catalyst, the metal M in the formula (A) is a lanthanoid element, scandium, or yttrium. The lanthanoid elements include 15 elements having atomic numbers 57 to 71, and any of these may be used. Preferred examples of the metal M include samarium Sm, neodymium Nd, praseodymium Pr, gadolinium Gd, cerium Ce, holmium Ho, scandium Sc, and yttrium Y.

  In the formula (A), each R is independently an unsubstituted indenyl or a substituted indenyl, and the R is coordinated to the metal M. Specific examples of the substituted indenyl group include 1,2,3-trimethylindenyl group, heptamethylindenyl group, 1,2,4,5,6,7-hexamethylindenyl group, and the like. It is done.

  In the above formula (A), Q represents a group 13 element in the periodic table, and specific examples include boron, aluminum, gallium, indium, thallium and the like.

  In the above formula (A), each X independently represents a hydrocarbon group having 1 to 20 carbon atoms, and X is μ-coordinated to M and Q. Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like. Note that the μ coordination is a coordination mode having a crosslinked structure.

  In the formula (A), each Y independently represents a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom, and the Y is coordinated to Q. Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like.

In the above formula (XV), the metal M ¹ is a lanthanoid element, scandium or yttrium. The lanthanoid elements include 15 elements having atomic numbers 57 to 71, and any of these may be used. Preferred examples of the metal M ¹ include samarium Sm, neodymium Nd, praseodymium Pr, gadolinium Gd, cerium Ce, holmium Ho, scandium Sc, and yttrium Y.

In the above formula (XV), Cp ^R is unsubstituted indenyl or substituted indenyl. Cp ^R having an indenyl ring as a basic skeleton can be represented by C ₉ H _7X R _X or C ₉ H _11X R _X. Here, X is an integer of 0-7 or 0-11. In addition, each R is preferably independently a hydrocarbyl group or a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group.
Specific examples of the substituted indenyl include 2-phenylindenyl and 2-methylindenyl. Incidentally, the two Cp ^R in the formula (XV) may each be the same or different from each other.

In the above formula (XV), R ^A and R ^B each independently represent a hydrocarbon group having 1 to 20 carbon atoms, said R ^A and R ^B is coordinated μ to M ¹及A ^l . Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like. Note that the μ coordination is a coordination mode having a crosslinked structure.

In the above formula (XV), R ^C and R ^D are each independently a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like.

（式中、Ｍ²は、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^Rは、それぞれ独立して無置換もしくは置換インデニルを示し、Ｒ^E〜Ｒ^Jは、それぞれ独立して炭素数１〜３のアルキル基又は水素原子を示し、Ｌは、中性ルイス塩基を示し、ｗは、０〜３の整数を示す）で表されるメタロセン錯体を、ＡｌＲ^KＲ^LＲ^Mで表される有機アルミニウム化合物と反応させることで得られる。なお、反応温度は室温程度にすればよいので、温和な条件で製造することができる。また、反応時間は任意であるが、数時間〜数十時間程度である。反応溶媒は特に限定されないが、原料及び生成物を溶解する溶媒であることが好ましく、例えばトルエンやヘキサンを用いればよい。なお、上記メタロセン系複合触媒の構造は、¹Ｈ−ＮＭＲやＸ線構造解析により決定することが好ましい。 The metallocene composite catalyst is, for example, in a solvent in the following formula (XVI):

(In the formula, M ² represents a lanthanoid element, scandium or yttrium, Cp ^R each independently represents an unsubstituted or substituted indenyl group, and R ^{E to} R ^J each independently represents a group having 1 to 3 carbon atoms. an alkyl group or a hydrogen atom, L is a neutral Lewis base, w is, the metallocene complex represented by an integer of 0 to 3), an organoaluminum compound represented by AlR ^K R ^L R ^M It is obtained by reacting with. In addition, since reaction temperature should just be about room temperature, it can manufacture on mild conditions. The reaction time is arbitrary, but is about several hours to several tens of hours. The reaction solvent is not particularly limited, but is preferably a solvent that dissolves the raw material and the product. For example, toluene or hexane may be used. The structure of the metallocene composite catalyst is preferably determined by ¹ H-NMR or X-ray structural analysis.

In the metallocene complex represented by the above formula (XVI), Cp ^R is unsubstituted indenyl or substituted indenyl, and has the same meaning as Cp ^R in the above formula (XV). In the above formula (XVI), the metal M ² is a lanthanoid element, scandium or yttrium, and has the same meaning as the metal M ¹ in the above formula (XV).

The metallocene complex represented by the above formula (XVI) contains a silylamide ligand [—N (SiR ₃ ) ₂ ]. The R groups (R ^{E to} R ^J groups) contained in the silylamide ligand are each independently an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. Moreover, it is preferable that at least one of R ^{E to} R ^J is a hydrogen atom. By making at least one of R ^{E to} R ^J a hydrogen atom, the catalyst can be easily synthesized. Furthermore, a methyl group is preferable as the alkyl group.

  The metallocene complex represented by the above formula (XVI) further contains 0 to 3, preferably 0 to 1, neutral Lewis bases L. Here, examples of the neutral Lewis base L include tetrahydrofuran, diethyl ether, dimethylaniline, trimethylphosphine, lithium chloride, neutral olefins, neutral diolefins, and the like. Here, when the complex includes a plurality of neutral Lewis bases L, the neutral Lewis bases L may be the same or different.

  In addition, the metallocene complex represented by the above formula (XVI) may exist as a monomer, or may exist as a dimer or a higher multimer.

On the other hand, the organoaluminum compound used for the production of the metallocene composite catalyst is represented by AlR ^K R ^L R ^M , where R ^K and R ^L are each independently a monovalent carbon atom having 1 to 20 carbon atoms. R ^M is a hydrogen group or a hydrogen atom, and R ^M is a monovalent hydrocarbon group having 1 to 20 carbon atoms, provided that R ^M may be the same as or different from R ^K or R ^L described above. Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group and tetradecyl group. , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like.

  Specific examples of the organoaluminum compound include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, tripentylaluminum, Hexyl aluminum, tricyclohexyl aluminum, trioctyl aluminum; diethyl aluminum hydride, di-n-propyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, dihexyl aluminum hydride, diisohexyl aluminum hydride , Dioctylaluminum hydride, diisooctylaluminum hydride; ethylaluminum dihydride, n-propylaluminium Dihydride, isobutyl aluminum dihydride and the like. Among these, triethylaluminum, triisobutylaluminum, hydrogenated diethylaluminum, hydrogenated diisobutylaluminum are preferred. Moreover, these organoaluminum compounds can be used individually by 1 type, or 2 or more types can be mixed and used for them. The amount of the organoaluminum compound used for the production of the metallocene composite catalyst is preferably 1 to 50 times mol, and more preferably about 10 times mol to the metallocene complex.

  The third polymerization catalyst composition contains the metallocene composite catalyst and a boron anion, and further contains other components such as an auxiliary contained in the polymerization catalyst composition containing a normal metallocene catalyst. It preferably contains a catalyst or the like. The metallocene composite catalyst and boron anion are also referred to as a two-component catalyst. According to the third polymerization catalyst composition, since the boron anion is further contained in the same manner as the metallocene composite catalyst, the content of each monomer component in the polymer can be arbitrarily controlled. It becomes.

  In the third polymerization catalyst composition, specific examples of the boron anion constituting the two-component catalyst include a tetravalent boron anion. For example, tetraphenylborate, tetrakis (monofluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis (pentafluorophenyl) borate, tetrakis (tetrafluoromethyl) Phenyl) borate, tetra (tolyl) borate, tetra (xylyl) borate, (triphenyl, pentafluorophenyl) borate, [tris (pentafluorophenyl), phenyl] borate, tridecahydride-7,8-dicarboundecaborate Among these, tetrakis (pentafluorophenyl) borate is preferable.

  In addition, the said boron anion can be used as an ionic compound combined with the cation. Examples of the cation include a carbonium cation, an oxonium cation, an amine cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation having a transition metal. Examples of the carbonium cation include trisubstituted carbonium cations such as a triphenylcarbonium cation and a tri (substituted phenyl) carbonium cation. The tri (substituted phenyl) carbonyl cation is specifically exemplified by tri (methylphenyl). ) Carbonium cation and the like. Examples of amine cations include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, and tributylammonium cation; N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N- N, N-dialkylanilinium cations such as 2,4,6-pentamethylanilinium cation; dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation. Examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri (methylphenyl) phosphonium cation, and tri (dimethylphenyl) phosphonium cation. Among these cations, N, N-dialkylanilinium cation or carbonium cation is preferable, and N, N-dialkylanilinium cation is particularly preferable. Therefore, as the ionic compound, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis (pentafluorophenyl) borate and the like are preferable. The ionic compound composed of a boron anion and a cation is preferably added in an amount of 0.1 to 10 times mol, more preferably about 1 time mol based on the metallocene composite catalyst.

  In the third polymerization catalyst composition, the metallocene composite catalyst and the boron anion need to be used. If a boron anion is present, the metallocene composite catalyst of the above formula (XV) cannot be synthesized. Therefore, for the preparation of the third polymerization catalyst composition, it is necessary to synthesize the metallocene composite catalyst in advance, isolate and purify the metallocene composite catalyst, and then combine with the boron anion.

Examples of the third polymerization catalyst co-catalyst which can be used in the compositions, for example, other organic aluminum compound represented by AlR ^K R ^L R ^M described above, aluminoxane can be preferably used. The aluminoxane is preferably an alkylaminoxan, and examples thereof include methylaluminoxane (MAO) and modified methylaluminoxane. As the modified methylaluminoxane, MMAO-3A (manufactured by Tosoh Finechem Co., Ltd.) and the like are preferable. These aluminoxanes may be used alone or in combination of two or more.

--Coupling process--
The coupling step is a step of performing a reaction (coupling reaction) for modifying at least a part (for example, a terminal) of the polymer chain of the copolymer obtained in the polymerization step.
In the coupling step, the coupling reaction is preferably performed when the polymerization reaction reaches 100%.
There is no restriction | limiting in particular as a coupling agent used for the said coupling reaction, According to the objective, it can select suitably, For example, tin, such as (i) bis (1-octadecyl maleate) dioctyl tin (IV), etc. And (ii) isocyanate compounds such as 4,4′-diphenylmethane diisocyanate, (iii) alkoxysilane compounds such as glycidylpropyltrimethoxysilane, and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, bis (-1-octadecyl maleate) dioctyltin (IV) is preferable in terms of reaction efficiency and low gel formation.
In addition, the number average molecular weight (Mn) can be increased by performing a coupling reaction.

-Cleaning process-
The washing step is a step of washing the styrene-isoprene copolymer obtained in the polymerization step. The medium used for washing is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include methanol, ethanol, isopropanol and the like. When a catalyst derived from a Lewis acid is used as a polymerization catalyst. Can be used in particular by adding an acid (for example, hydrochloric acid, sulfuric acid, nitric acid) to these solvents. The amount of the acid to be added is preferably 15 mol% or less with respect to the solvent. Above this, the acid remains in the polymer, which may adversely affect the reaction during kneading and vulcanization.
By this washing step, the amount of catalyst residue in the synthetic polyisoprene can be suitably reduced.

(Rubber composition)
The rubber composition of the present invention includes at least a rubber component, and further includes a filler, a crosslinking agent, and other components as necessary.

-Rubber component-
The rubber component includes at least the styrene-isoprene copolymer, and further includes other rubber components as necessary. The styrene-isoprene copolymer is preferably contained in an amount of 50 parts by weight or more, particularly 50 to 100 parts by weight, and more preferably 70 to 100 parts by weight with respect to 100 parts by weight of the rubber component. By blending 50 parts by weight or more of the above styrene-isoprene copolymer, it is possible to provide a rubber composition having improved durability (destructive properties, wear resistance, and crack growth resistance). Play.

The synthetic styrene-isoprene copolymer is as described above.
The total blending amount (total content) of the polymer (the synthetic polyisoprene, the isoprene copolymer, or the synthetic polyisoprene and the isoprene copolymer) in the rubber component is not particularly limited. Although it can select suitably according to, 15 mass%-100 mass% are preferable.
The characteristic of the said polymer can fully be exhibited as the total compounding quantity of the said polymer in the said rubber component is 15 mass% or more.

-Other rubber components-
There is no restriction | limiting in particular as said other rubber | gum, According to the objective, it can select suitably, For example, polyisoprene, butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber, ethylene-propylene rubber ( EPM), ethylene-propylene-nonconjugated diene rubber (EPDM), polysulfide rubber, silicone rubber, fluorine rubber, urethane rubber, and the like. These may be used individually by 1 type and may use 2 or more types together.

-Filler-
There is no restriction | limiting in particular as said filler, According to the objective, it can select suitably, For example, carbon black, an inorganic filler, etc. can be mentioned, At least 1 type selected from carbon black and an inorganic filler is mentioned. Is preferred. Here, it is more preferable that the rubber composition contains carbon black. In addition, the said filler is mix | blended with a rubber composition in order to improve reinforcement property etc.

There is no restriction | limiting in particular as a compounding quantity (content) of the said filler, Although it can select suitably according to the objective, 10-100 mass parts is preferable with respect to 100 mass parts of rubber components, 20 mass parts- 80 mass parts is more preferable, and 30 mass parts-60 mass parts is especially preferable.
When the blending amount of the filler is less than 10 parts by mass, the effect of adding the filler may not be seen so much, and when it exceeds 100 parts by mass, the rubber component tends not to be mixed. The performance as a rubber composition may be lowered.

--Carbon black--
There is no restriction | limiting in particular as said carbon black, According to the objective, it can select suitably, For example, FEF, GPF, SRF, HAF, N339, IISAF, ISAF, SAF etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
The nitrogen adsorption specific surface area of the carbon black (measured in accordance with N ₂ SA, JIS K 6217-2: 2001) is not particularly limited and may be appropriately selected depending on the intended purpose. ² / g is preferable, and 35-80 m < ² > / g is more preferable.
Wherein the carbon black nitrogen adsorption specific surface area (N 2 _SA) is less than 20 m 2 / ^g, low durability of the resulting rubber, may not sufficiently crack growth resistance is obtained, 100 m ² / When it exceeds g, low loss property falls and workability | operativity may be bad.
There is no restriction | limiting in particular as content of carbon black with respect to 100 mass parts of said rubber components, Although it can select suitably according to the objective, 10-100 mass parts is preferable, 10-70 mass parts is more preferable, 20 -60 mass parts is especially preferable.
If the carbon black content is less than 10 parts by mass, the reinforcing property may be insufficient and the fracture resistance may deteriorate, and if it exceeds 100 parts by mass, the workability and low loss property may deteriorate. is there.
On the other hand, when the content of the carbon black is within the more preferable range, it is advantageous in terms of the balance of each performance.

--Inorganic filler--
The inorganic filler is not particularly limited and may be appropriately selected depending on the intended purpose.For example, silica, aluminum hydroxide, clay, alumina, talc, mica, kaolin, glass balloon, glass beads, calcium carbonate, Examples thereof include magnesium carbonate, magnesium hydroxide, calcium carbonate, magnesium oxide, titanium oxide, potassium titanate, and barium sulfate. These may be used individually by 1 type and may use 2 or more types together.
In addition, when using an inorganic filler, you may use a silane coupling agent suitably.

-Crosslinking agent-
There is no restriction | limiting in particular as said crosslinking agent, According to the objective, it can select suitably, For example, a sulfur type crosslinking agent, an organic peroxide type crosslinking agent, an inorganic crosslinking agent, a polyamine crosslinking agent, a resin crosslinking agent, sulfur Compound-based crosslinking agents, oxime-nitrosamine-based crosslinking agent sulfur, and the like can be mentioned. Among these, sulfur-based crosslinking agents are more preferable as the rubber composition for tires.

There is no restriction | limiting in particular as content of the said crosslinking agent, Although it can select suitably according to the objective, 0.1-20 mass parts is preferable with respect to 100 mass parts of rubber components.
When the content of the cross-linking agent is less than 0.1 parts by mass, the cross-linking hardly proceeds, and when the content exceeds 20 parts by mass, the cross-linking tends to proceed during kneading with some cross-linking agents. Or the physical properties of the vulcanizate may be impaired.

-Other ingredients-
In addition, it is also possible to use a vulcanization accelerator in combination, and examples of the vulcanization accelerator include guanidine, aldehyde-amine, aldehyde-ammonia, thiazole, sulfenamide, thiourea, thiuram, Dithiocarbamate and xanthate compounds can be used.
If necessary, softeners, vulcanization aids, colorants, flame retardants, lubricants, foaming agents, plasticizers, processing aids, antioxidants, anti-aging agents, scorch inhibitors, UV inhibitors, antistatic agents Known agents such as a colorant, an anti-coloring agent, and other compounding agents can be used depending on the purpose of use.

(Crosslinked rubber composition)
The crosslinked rubber composition is not particularly limited as long as it is obtained by crosslinking the rubber composition of the present invention, and can be appropriately selected according to the purpose.
The crosslinking conditions are not particularly limited and may be appropriately selected depending on the intended purpose. However, a temperature of 120 to 200 ° C. and a heating time of 1 minute to 900 minutes are preferable.

(tire)
The tire of the present invention is not particularly limited as long as the rubber composition of the present invention or the crosslinked rubber composition of the present invention is used, and can be appropriately selected according to the purpose.
The application site in the tire of the rubber composition of the present invention or the crosslinked rubber composition of the present invention is not particularly limited and can be appropriately selected depending on the purpose, for example, tread, base tread, sidewall, Examples include side reinforcing rubber and bead filler.
Among these, it is advantageous in terms of durability that the application site is a tread.
As a method for manufacturing the tire, a conventional method can be used. For example, on a tire molding drum, members normally used for manufacturing tires such as a carcass layer, a belt layer, a tread layer and the like made of an unvulcanized rubber composition and / or a cord are sequentially laminated, and the drum is removed and a green tire is removed. To do. Then, a desired tire (for example, a pneumatic tire) can be manufactured by heating and vulcanizing the green tire according to a conventional method.

(Applications other than tires)
Besides the tire application, the rubber composition of the present invention or the crosslinked rubber composition of the present invention can be used for anti-vibration rubber, seismic isolation rubber, belt (conveyor belt), rubber crawler, various hoses and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Production Example 1: Production method of polymer A (synthetic polyisoprene))
In a 1 L pressure-resistant glass reactor in a glove box under a nitrogen atmosphere, trisbistrimethylsilylamidogadolinium [GdN (SiMe ₃ ) ₂ ] ₃ 7.35 μmol, bis (2-diphenylphosphinophenyl) amine 7.35 μmol and toluene 1. After adding 0 g and aging for 30 minutes, 1.84 mmol of triisobutylaluminum and 5.0 g of toluene were added, followed by further aging for 30 minutes. Thereafter, 7.35 μmol of triphenylcarbonium tetrakis (pentafluorophenyl) borate (Ph ₃ CB (C ₆ F ₅ ) ₄ ) was added and aged for 15 minutes. Thereafter, the reactor was taken out of the glove box, 164.7 g of cyclohexane and 65 g of isoprene were added, and polymerization was carried out at 50 ° C. for 2 hours. After the polymerization, 2 mL of 2,2′-methylene-bis (4-ethyl-6-t-butylphenol) (NS-5) 5% by mass of isopropanol solution was added to stop the reaction, and the polymer was separated with a large amount of methanol. And dried under vacuum at 70 ° C. to obtain a copolymer. The yield of the obtained copolymer was 65 g.

(Production Example 2: Production method of polymer B (styrene-isoprene copolymer))
In a 1 L pressure-resistant glass reactor in a glove box under a nitrogen atmosphere, 9.43 μmol of trisbistrimethylsilylamidogadolinium [GdN (SiMe ₃ ) ₂ ] _3, 9.43 μmol of bis (2-diphenylphosphinophenyl) amine and 1. After adding 0 g and aging for 30 minutes, after charging 1.41 mmol of triisobutylaluminum and 5.0 g of toluene, aging was further performed for 30 minutes. Thereafter, 7.35 μmol of triphenylcarbonium tetrakis (pentafluorophenyl) borate (Ph ₃ CB (C ₆ F ₅ ) ₄ ) was added and aged for 15 minutes. Thereafter, the reactor was taken out from the glove box, 1.7 g of styrene was added, and the mixture was stirred at 50 ° C. for 30 minutes. Thereafter, 163.0 g of cyclohexane and 65 g of isoprene were added, and polymerization was carried out at 50 ° C. for 2 hours. After polymerization, 1 mL of 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (NS-5) 5% by mass isopropanol solution was added to stop the reaction, and the polymer was further added with a large amount of methanol. Separation and vacuum drying at 70 ° C. gave a polymer B. The yield of the obtained polymer B was 59 g.

(Production Example 3: Production method of polymer C (styrene-isoprene copolymer))
In a 1 L pressure-resistant glass reactor in a glove box under a nitrogen atmosphere, 9.43 μmol of trisbistrimethylsilylamidogadolinium [GdN (SiMe ₃ ) ₂ ] _3, 9.43 μmol of bis (2-diphenylphosphinophenyl) amine and 1. After adding 0 g and aging for 30 minutes, after adding 1.41 mmol of triisobutylaluminum and 5.0 g of toluene, aging was further performed for 30 minutes, and then triphenylcarbonium tetrakis (pentafluorophenyl) borate (Ph ₃ CB). 7.35 μmol of (C ₆ F ₅ ) ₄ ) was added and aged for 15 minutes. Thereafter, the reactor was taken out from the glove box, 3.4 g of styrene was added, and the mixture was stirred at 50 ° C. for 30 minutes. Thereafter, 161.4 g of cyclohexane and 65 g of isoprene were added, and polymerization was carried out at 50 ° C. for 2 hours. After the polymerization, 2 mL of 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (NS-5) 5% by mass of isopropanol solution was added to stop the reaction, and the polymer was separated with a large amount of methanol. The polymer C was obtained by vacuum drying at 70 ° C. The yield of the obtained polymer C was 62 g.

（式中、ａは、フーリエ変換赤外分光法（ＦＴ−ＩＲ）による透過率スペクトルの１１３０ｃｍ^−１付近の山ピーク値であり、ｂは、９６７ｃｍ^−１付近の谷ピーク値であり、ｃは、９１１ｃｍ^−１付近の谷ピーク値であり、ｄは、７３６ｃｍ^−１付近の谷ピーク値である）から導かれるｅ，ｆ，ｇの値を用い、下記式（ｉｖ）
（シス−１，４結合量の計算値＝ｅ／（ｅ＋ｆ＋ｇ）×１００ ・・・（ｉｖ）
にしたがって、シス−１，４結合量の計算値を求めた。 The obtained polymers A to C were analyzed for their microstructure, isoprene content, number average molecular weight (Mn), molecular weight distribution (Mw / Mn), and glass transition temperature (Tg). Each analysis result of the polymers A to C is shown in Table 1.
(1) Microstructure of polymers A to C (cis-1,4 bond amount)
The microstructures (cis-1,4 bonds) of the polymers A to C were calculated by measuring the transmittance spectrum of Fourier transform infrared spectroscopy (FT-IR). Specifically, the transmittance spectrum by FT-IR of the carbon disulfide solution of each polymer adjusted to a concentration of 5 mg / mL as a carbon disulfide blank in the same cell was measured, and the following determinant (iii):

(In the formula, a is a peak peak value in the vicinity of 1130 cm ⁻¹ of the transmittance spectrum by Fourier transform infrared spectroscopy (FT-IR), b is a valley peak value in the vicinity of 967 cm ⁻¹ , and c is a valley peak value around 911 cm ^-1, d is, e derived from 736cm ^-1 is a valley peak value around), f, using the value of g, the following formula (iv)
(Calculated value of cis-1,4 bond amount = e / (e + f + g) × 100 (iv)
Thus, the calculated value of cis-1,4 bond amount was determined.

(2) Number average molecular weight (Mn) and molecular weight distribution (Mw / Mn)
Gel permeation chromatography [GPC: Tosoh HLC-8121GPC / HT, column: Tosoh GMH _HR- H (S) HT × 2, detector: differential refractometer (RI)] on the basis of monodisperse polystyrene The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) in terms of polystyrene of the polymers A to C were determined. The measurement temperature is 40 ° C.

(3) Glass transition temperature A plate-like polymer for measuring glass transition temperature of about 60 × 10 × 1 mm was prepared, and a dynamic viscoelasticity test was conducted under the conditions of a heating rate of 3 ° C./min and a frequency of 1 Hz. From the peak, the glass transition temperature of the adhesive resin composition was measured.

<Evaluation method of rubber composition>
A crosslinked rubber composition obtained by preparing a rubber composition having the formulation shown in Table 2 and vulcanizing at 160 ° C. for 20 minutes was subjected to the following methods in accordance with (1) fracture resistance and (2) abrasion resistance. (3) Crack growth resistance (constant stress) was measured. The measurement results are shown in Table 2.

(1) Fracture resistance (index)
A tensile test was performed at room temperature in accordance with JIS K 6301-1995, the tensile strength (Tb) of the vulcanized rubber composition was measured, and the index when the tensile strength of Comparative Example 1 was set to 100 was shown in Table 2. Shown in The larger the index value, the better the fracture resistance.

(2) Abrasion resistance (index)
A DIN abrasion test was performed in accordance with JIS-K6264-2: 2005 using a test piece cut into a disc shape (diameter: 16.2 mm × thickness: 6 mm) from each prepared vulcanized rubber. The amount of wear (mm ³ ) when a DIN wear test was performed at room temperature was measured. Table 2 shows the index (reciprocal of the amount of wear) when Comparative Example 1 is 100. It shows that abrasion resistance is so favorable that an index value is large.

(3) Crack growth resistance (index) (constant strain)
The number of times until a sample is cut by making a 0.5 mm crack at the center of a JIS No. 3 test piece, giving repeated fatigue at a constant strain of 100% strain (measured by a tensile test according to JIS K6251) at room temperature. It was measured. The results are shown in Table 2. A larger index value indicates better crack growth resistance. In the table,> 200 indicates that the sample was not cut even when the comparative example 1 was subjected to repeated fatigue twice as many times.

  From Table 2, in Examples 1-6 which are vulcanized rubber compositions using a styrene-isoprene copolymer (polymers B and C), compared with synthetic polyisoprene (polymer A) and butadiene rubber, A crosslinked rubber composition having improved durability (destructive properties, abrasion resistance, and crack growth resistance) could be obtained.

  The copolymer of the present invention and the rubber composition containing the copolymer can be suitably used for, for example, a tire member (particularly, a tread member of a tire).

Claims (7)

A styrene-isoprene copolymer having a styrene block at the end ,
The proportion of the styrene monomer in the total monomer constituting the copolymer is 1.7 to 3.3 mol% ,
A styrene-isoprene copolymer characterized in that the total amount of cis-1,4 bonds in the isoprene-derived portion is 95% or more.   The styrene-isoprene copolymer according to claim 1, wherein the number of styrene monomer units per styrene block is 10 or less.   The styrene-isoprene copolymer according to claim 1, wherein the molecular weight per styrene block is 1000 or less. Formula (i) below:
M- (NQ) ¹ (NQ) ² (NQ) ³ (i)
(In the formula, M is at least one selected from lanthanoids, scandium and yttrium, and NQ ¹ , NQ ² and NQ ³ are amide groups, which may be the same or different, provided that MN A polymer or oligomer is synthesized by polymerizing a styrene monomer at −100 ° C. to 200 ° C. in the presence of a catalyst containing a rare earth element compound represented by (having a bond), and isoprene monomer is added to the polymer or oligomer A method for producing a styrene-isoprene copolymer that is polymerized at -100 ° C to 200 ° C ,
The proportion of the styrene monomer in the total monomer constituting the styrene-isoprene copolymer is 1.7 to 3.3 mol% , and the total amount of cis-1,4 bonds in the portion derived from isoprene is 95% or more. , A method for producing a styrene-isoprene copolymer. Furthermore, the additive D which can become an anionic ligand is added, The manufacturing method of the styrene-isoprene copolymer of Claim 4 . A rubber composition comprising a rubber component, wherein the rubber component contains 50 parts by weight or more of the copolymer according to any one of claims 1 to 3 with respect to 100 parts by weight of the rubber component. . A tire provided with a rubber member using the rubber composition according to claim 6 .